Control mechanism for honing machines



H. J. CALDWELL ETAL CONTROL MECHANISM FOR HONING,.MACHINES March 9, 19542 Sheets-Sheet 1 Filed May 23, 1950 g 5 3 km a; 5 M; i

arch 9, 1954 H. J. CALDWELL arm. 2,671,292

CONTROL MECHANISM FOR HONING MACHINES Filed May 25, 1950 2 Sheets-Sheet2 InVent'bv-J Harv-y J. Caldwell (lav-e St csebcv Patented Mar. 9, 1954UNITED STATES PATENT OFFICE CONTROL MECHANISM FOR HONING MACHINES HarryJ Caldwell and Earnest Y. Seborg, Rockford, Ill., assig'nors to BarnesDrill 00., Rockford, III., a corporation of Illinois Application May 23,1950, Serial No. 163,578

'7 Claims. I

The invention relates to machines for finishing elongated bores by ahoning or lap-ping operation, and more particularly to control mechanismfor such machines. 7

In a honing or lapping operation a radially expansible cylindricalabrasive tool and a workpiece are relatively rotated and simultaneouslyrelatively reciprocated axially of the bore in the workpiece which is tobe finished. During such rotation and reciprocation, the abrasiveelements of the tool expand into operative engagement with the walls ofthe bore. The amount of material removed from the bore walls and thusits finished diameter is determined in part by the number of times thetool is traversed over the walls. It will be apparent, therefore, thatwhen the tool is traversed only part way through the bore, more materialwill be removed from the walls adjacent the entering end than from theopposite end, with a corresponding increase in the diameter of the boreat such entering end.

The primary object of the present invention is to provide improvedcontrol mechanism whereby the above principle may be utilized toadvantage in generating tapered or stepped surfaces in bores initiallymachined to cylindrical contour.

More specifically stated, an object of the invention is to providecontrol mechanism operative automatically to reduce the length of thetool stroke progressively by predetermined increments so as to generatea bore of gradually increasing diameter.

Another object is to provide a control mechanism of the above generalcharacter which is readily adjustable to produce a; wide range ofsurface finishes including, on one hand, a finish in which the steppedareas of the surface are so short measured axially of the bore as toafford a substantially uniform taper from one end of the bore to theother, or alternatively, a finish in which the stepped areas arerelatively long and prominent.

It is also an object of the invention to provide stroke controlmechanism for honing machines which is simple in construction,eflicient' and dcpendable in operation and which can be applied toconventional honing machines to increase their utility without afiectingtheir normal mode of operation.

Other objects and advantages of the invention will become apparent fromthe following detailed description of the preferred embodiment illustrated in the accompanying drawings, in which:

Figure 1 is an elevational view of a control mechanism embodying thefeature of the inven- 2 tion, the mechanism being shown as applied to aconventional horizontal honing machine. v v

Fig. 2 is a fragmentary sectional view taken in a vertical planesubstantially on the line 2-4 of Fig. 1.

Fig. 3 is a. fragmentary sectional view taken in a horizontal planesubstantially on the line 3-3 of Fig. 1. v

Fig. 4 is a diagrammatic view showing the electrical and hydraulicoperating control cir+ cults of the machine shown in Fig. 1. I

While the approved controls are applicable to various types of honingand lapping machines, they are particularly suitable for use withmachines designed for operating on long workpieces which are desirablyhandled in a horizontal po sition. It will be understood, of course,-that various changes and modifications may be made in the form,construction and arrangement of the parts of the control mechanismwithout depart ing from the spirit and scope of the invention asexpressed in the appended claims.

For purposes of illustration, the invention has been shown asincorporated in a horizontal hon ing machine of the type disclosed inthe Caldwell Patent No. 2,247,479 issued July 1, 1941, in which the workis stationarily supported and the honing tool is rotated andreciprocated relative thereto. The exemplary machine comprises anelongated, horizontally disposed bed It (Fig. 1) having means at one endfor supporting a work piece W (Fig. 4) formed with a bore B to be"finished, and having means at the other end for supporting a honing toolT. The tool support comprises a head or carriage ll mounted forreciprocation so as to traverse the tool T anially of the bore B. Thetool T is carried on the pro jecting end of an elongated driver I2secured to and rotatable with a spindle l3 journalled on the head II. Amotor M mountedon the head is operative through suitable gearingeaclosed Within a housing [4' to rotate the spindle [3 eithercontinuously or intermittently.

The tool T, as shown, is a conventional honing tool having a cylindricalbody 15' about which are arranged a series of elongated,- longitudinally disposed abrasive elements l6, These abrasive elements are movableradially of the tool body into and out of operative engagement with thewalls of the bore. Such movements of the abrasive elements to expand orcontract the tool may be effected in any preferred manner;- as;

for example; by power operated mechanism such 2,171,261- issued- August28,1939.

Suitable power operated means is provided for reciprocating the head Thereciprocating means as shown in Fig. 4 comprises a pair of flexiblemembers or cables 20 and 2|, each anchored at one end to an arm 22depending from the head and at the other end to a cable drum 23rotatably supported adjacent the end of the bed l remote from the worksupport. The cable leads directly from the head to the drum while thecable 2| is carried over a sheave 24 rotatably supported on the bed I8below the work support. The arrangement is such that rotation of thedrum 23 first in one direction and then in the other direction iseffective to move the head toward and from the work, or in other words,to reciprocate the head.

Rotation of the cable drum 23 is preferably effected by means of ahydraulic motor HM, herein shown as drivingly connected with the drumthrough the medium of gearing 25. Pressure fluid is supplied to themotor HM by a motor driven pump P under control of a reversing valve RV.The particular reversing valve illustrated is pressure fluid operatedunder control of a pilot valve PV which, in turn, is actuatedmechanically as an incident to the reciprocation of the head I Themechanism for actuating the pilot valve PV as herein shown comprises anelongated control rod 28 extending along the side of the bed l0 parallelto the path of reciprocation of the head H and supported on the bed torock about its longitudinal axis. Such movements of the control rod aretransmitted to the movable member of the pilot valve through the mediumof a gear 21, pinion 28, rockshaft 29, crank arm 3!], link 3| and crankarm 32 associated with such movable member. rocked alternately inopposite directions, the pilot valve PV is shifted to set the reversingvalve RV for initiating the forward and return movements of the head.

The rocking of the control rod is effected by the head through themedium of a pair of cam elements 34 and 35 reciprocable with the headand engageable respectively with a pair of actuating members comprising,in this instance, a rear dog 31 and a front dog 38 operativelyassociated with the control rod. As herein shown, the cams 34 and 35 arecarried by an arm 39 depending from the head, the cams being opposedlyfaced so as to shift the dogs in opposite directions. More particularlythe arrangement is such that th cam 34 engages the dog 3'! to rock thecontrol rod in one direction (for example, counterclockwise) as the headapproaches the end of its stroke whil moving toward retracted position,or to the right as viewed in Fig. 4. As the head approaches the otherend of its stroke, the cam 35 engages the dog 38 to rock the control rodin the opposite direction.

The dogs 3! and 38 may be alike, in construction. In the exemplaryembodiment, each comprises an arm 40 rigidly clamped to and projectingradially from a shaft 4| supported for rocking movement in a bracket 42at the side of the machin bed adjacent the contro1 rod. A followerroller 43 is desirably provided on the outer end of each arm 48 forengagement by the associated cam.

Each shaft 4| carries a segmental gear element 44 meshing withlongitudinal teeth or splines 45 formed on the control rod. With thisarrangement, the rocking movement imparted to either dog by engagementof its cam correspondingly rocks the control rod and thus shiftsthe-pilot Thus, as the control rod is valv between forward and returnstroke positions.

The toothed connection between the control rod 26 and the dogs 31 and 38permits the latter to b mounted for adjustment longitudinally of the rodwhereby to change the limit positions of the head II at opposite ends ofits stroke. For this purpose the brackets 42 which support the two dogs31 and 38 are mounted respectively on carriers 46 and 41 which areslidably supported on a guide bar 48 extending longitudinally of the bedIf] below the control rod.

The carrier 46 may be conveniently constructed in the form of a channelshaped memu ber presenting inwardly facing bearing surfaces at its upperand lower ends for sliding engagement with the corresponding surfaces ofthe guide bar 48. A tapered gib 49 adjustable by means of a screw 50 isprovided between the upper bearing and guide surfaces for insuring asnug fit and for taking up wear. In operation the carrier 46 may besecurely clamped in a fixed position of adjustment, as by means of clampscrews 5|.

The carrier 4! is generally similar to the carrier 46 in having upperand lower bearing surfaces cooperating with the corresponding guidesurfaces of the guide bar 48. A tapered gib 52 and adjusting screw 53 isprovided for adjusting the fit between the bearing and guide surfacesand for taking up wear.

In accordance with the invention, control of the tool stroke fordistributing tool action in the manner required to generate a tapered orstepped surface is effected by shifting the carrier 41 and with it thefront dog 38 so as to periodically decrease the length of the forwardstroke by predetermined increments. Accordingly the tool action onsuccessive areas of the workpiece and therefore the amount of materialremoved from such areas increases progressively from the smaller towardthe larger end of the bore as to produce a tapered or steppedconfiguration.

The means for shifting the dog carrier 4'! is. of course, power actuatedand, as herein shown, comprises an electric motor Ml mounted on theouter face of'the carrier and adapted to rotate a transverse shaft 55extending through and journaled on the carrier as shown in Figs. 1 and3. This shaft is provided on its inner end with a pinion 56 meshing witha rack 51 mounted on the underside of the guide bar 48.

The drive for the shaft 55, in this instance, includes conventionalspeed reduction gearing 51' (Fig. 4) enclosed in a housing 58, a pinion59 and a gear 60 rotatably mounted on the shaft 55 between a collar 6|and a clutch element 62 slidably but non-rotatably coupled to the shaftas by a key 63. The inner end of the clutch element and the adjacentface of the gear 50 are formed with cooperating clutch teeth 64 of whichthe rotative movements of the gear are transmitted to the clutch elementand by the latter to the shaft.

Through the medium of a nut 65 threaded on the outer end of the shaft,the clutch element 62 may be shifted into or out of engagement with thegear. With the clutch elements disengaged, the shaft 55 may be rotatedmanually through the medium of a hand crank applied to its squared outerend.

In generating a tapered or stepped surface, it is usually desirable tovary the tool stroke in in crements of uniform length and to effect suchvariations 'intimed relation to the reciprocation actress of the tool,as for example, at the end of either a forward or return stroke. To thisend. provision is made for initiating the operation of the motor M! asan incident to the reciprocation of the head II. Such control may beeffected by means of a suitable switch S (Fig. 4) mounted on the machinebed It for actuation by the head as it passes a predetermined pointin'its travel, pref erably as it approaches the limit position of itsreturn stroke.

Through the medium of novel auxiliary control mechanism, the length ofthe increment of change of the tool stroke and also the interval betweensuch changes may be varied as required by the character of the materialbeing worked on and by the particular surface contour to be producedthereon. For determining the interval between stroke changes andtherefore the number of working strokes applied to a selected area ofthe work, the switch S is arranged to actuate a stroke counter C which,in turn, initiates the operation of the motor M I. This stroke countermay be of any preferred type operative in response to a predeterminednumber of switch actuations to close a normally open switch S I. Thecounter, of course, is selectively adjustable by means of a knob or dial(it to effect closure of the switch SI following any desired number ofactuations of the switch S.

For determining the extent of movement of the dog carrier ii and thusthe length of the increment by which the tool stroke is changed,provision is made for independently controlling its operating period. Inthis instance, closure of switch Si by the counter C is arranged toinitiate the operation of a timer T simultaneously with the starting ofthe motor MI. The timer T may be of any preferred construction and ispreferably arranged to immediately close a switch S2 and to maintainthat switch closed for a predetermined interval as determined by thesetting of a selector knob or dial 61. Switch S2 when closed completesan energizing circuit for a solenoid SOL which closes a switch S3 tocomplete the operating circuit for the motor Mi. At the end of theinterval determined by the setting knob er, timer switch S2 is opened tointerrupt the circuit for the solenoid SOL which becomes disenergizedand stop the motor MI.

The various electrical elements of the control mechanism are desirablymounted on the machine bed it. for convenient access by the machineattendant. When so mounted, electrical connection with the motor Ml onthe movable carrier a": may be effected through the medium of slidingcontact elements or brushes H! (Fig. 4) carried by an arm ll (Fig. 1)depending from the carrier. The brushes cooperate with contact strips i2extending longitudinally of the machine bed 10.

It will be apparent that with the above arrangement the controls may beset to effect reciprocation of the tool through a series of strokeswhich progressively decrease in length. The number of strokes of any onelength and thus the amount of tool action on a particular area of thework may be selectively determined by the setting of the stroke counterC. The operating interval of the motor MI and thu length of theincrement of change in the length of the tool stroke may be varied byadjustment of the timer T. In other words, the stroke counter C andtimer T provide convenient means whereby the frequency of changes in thetool stroke and the increment of change in the length of the strokes maybe varied as required by the character of the work and particular finishto be produced thereon. Thus. when desired, adjustment of the dog 38 maybe effected in very small steps with correspondingly small incrementsof'change in the tool stroke. Withsuch small increments of change, thesuccessive surfaces produced on the work are so short measured axiallyof the work a to produce the effect of a substantially continuoustapered surface. Alternatively, by setting the timer T for asubstantially longer operating period, the dog 38 may be shifted fartherso as to amplify the increment of stroke reduction and thus producesuccessive stepped areas of substantial length.

Before a honing operation is started, the stroke counter C and timer '1are ordinarily preset to produce the desired surface contour. It will beappreciated that those settings can be changed at any time if uniformitybetween the successive stepped surfaces is not required. 7

It will be apparent from the foregoing that the invention provides novelcontrol mechanism for automatically varying the reciprocating stroke ofa honing tool to distribute the tool action over the surface of aworkpiece for producing a tapered or stepped contour thereon. Themechanism is simple in construction, free of parts that are sub-.

ject to wear or likely to get out of order, and is quickly and easilyadjustable to meet a wide range of operating conditions. In thisconnection it. will be noted that the mechanism is adjustable to varyboth the number of operating strokes applied to a selected surface ofthe work and also to vary the length of such surface as desired.Furthermore, the mechanism is readily attachable to conventional honingmachines or other. comparable machines without affecting their usualmode of operation, since the automatic control mechanism may betemporarily disconnected or shut off, thus allowing the regular controlsto function in the normal manner.

We claim as our invention:

1. In a honing machine having relatively rotatable and relativelyreciprocable work and tool supports, in combination, means operativelyconnected in driving relation to the reciprocable support, controlmechanism operatively connected with said driving means including acontrol rod supported to rock about its longitudinal axis, a pair ofcontrol dogs positioned so as to be rocked in opposite directionsrespectively as the reciprocable support approaches opposite ends of itsstroke, a gear element coupled to and rocked with each dog, andcircumferentially spaced teeth formed in said control rod operativelyengaging said gear elements whereby the rocking movements of said dogsare transmitted to the control rod.

2. In a honing machine having relatively rotatable and relativelyreciprocable work and tool supports, in combination, means operativelyconnected in driving relation tothe reciprocable support, controlmechanism operatively connected to said driving means including acontrol rod supported to rock about its longitudinal axis,circumferentially spaced teeth extending longitudinally of said controlrod, a pair of control dogs positioned so as to be rocked in oppositedirections respectively as the reciprocable support approaches oppositeends of its stroke, a gear element coupled to and rotatable with each ofsaid dogs, and means supporting said dogs with said gear elements inengagement with the teeth on said control rod, the supporting means forone of said dogs being adjustable longitudinally of said control rod tochange the length of the stroke executed by the reciprocable support.

3. In a honing machine having relatively rotatable and relativelyreciprocable work and tool supports, in combination, means operativelyconnected in driving relation to the reciprocable support, controlmechanism operatively connected to said driving means including acontrol rod supported to rock about its longitudinal axis,circumferentially spaced teeth extending longitudinally of said controlrod, a pair of control dogs positioned so as to be rocked in oppositedirections respectively as the reciprocable support approaches oppositeends of its stroke, a gear element coupled to and rotatable with each ofsaid dogs, a carrier supporting each dog with its associated gearelement operatively engaging the teeth on said control rod,one of saidcarriers being shiftable longitudinally of the control rod for changingthe length of the stroke executed by the reciprocable support, andalternatively available power and manually operable actuators forshifting said one carrier.

4. In a honing machine, the combination of, a reciprocable support, amember movable back and forth along a predetermined path in unison withsaid support, a pair of limit control devices spaced apart along saidpath for alternate acuation by said member and each operable whenactuated to reverse the direction of movement of said support, one ofsaid devices being mounted for movement toward and away from the otherdevice, a power actuator connected to said one device and operable whenenergized to move the same along said path, means including an elementactuated by said support at a predetermined point in the movement of thelatter to energize said power actuator thereby to move said one deviceand change the length of the stroke of said support, and means fordeenergizing said power actuator after a predetermined movement of saidone device.

5. Mechanism for a honing machine as defined in claim 4 in which saidpower actuator is deenergized by a timer operated automatically as anincident to the energization of the power actuator.

6. Mechanism for a honing machine as defined in claim 4 in which saidpower actuator is energized by a counter actuated by said element andoperable after a predetermined number of strokes of said support toenergize the power actuator and move said one device.

7. In a honing machine, the combination of, a reciprocable support, amember movable back and forth along a predetermined path in unison withsaid support, first and second control devices spaced apart along saidpath for alternate actuation by said member and each operable whenactuated to reverse the direction of movement of said support, saidfirst device being mounted for movement along said path, a poweractuator connected to said first device and 0perable when energized tomove the same along said path toward said second device, means includingan element actuated by said support at a point in the movement of thelatter adjacent said second device to energize said power actuator whensaid member is remote from said first device thereby to move said firstdevice toward said second device before the next actuation of the sameby said member, and means for deenergizing said power actuator after apredetermined movement of said first device.

HARRY J. CALDWELL. EARNEST Y. SEBORG.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 466,739 Finnegan Jan. 5, 1892 1,884,985 Van Hamersveld Oct.25, 1932 1,945,044 Johnson Jan. 30, 1934 1,954,155 Vlchek Apr. 10, 19341,954,157 Vlchek Apr. 10, 1934 2,111,784 Johnson Mar. 22, 1938 2,247,479Caldwell July 1, 1941 2,324,727 Shartle July 20, 1943 2,352,183 BullardJune 27, 1944 2,575,031 Smith Nov. 13, 1951

